Clutch



Aug 10, i943. c. BossMEYER ETAL .2,326,611

CLUTCH Filed oct. s, 1941 20 Y jg' e2 fgmnunungm;

l'llnl -ness of operation and a Patented Aug. 10, 1943 Charles L; Boss'me'y'elg Stratfordyjandf Simon` i s Yerkovich, Bridgeport, Conn.,` assignors to Diei Y Y Y' Corporation, New Yorlr,N. Y., a cor-' taphone f poration ofNewYork Application-bomber 8,1941, Serial No; 414,' Y'

` 2 claims. cl. isz- 23) This inventionV relates toplutcheaand par-s ticularly to clutches of the type usedto drive the k record support shafts of jconlmercialA phonographa such as di-ctatinggmachines.

In the now pending application, Serial No. 409,525, filed September, ;,4, 194i, by John'E.

Renholdt, assigner to Dictaphone-Corporation,

a corporationof New York, therewas disclosed ai drive mechanism for phono-graphs including a..

clutch of this type for transmitting. rotation from adrving element to a sound record support. In

that construction Va driving pulley;V loosely mounted on a record support shaft, carried a disengageable driving pawl normally springpressed into engagement with teeth distributed aboutthe periphery of a ratchet Wheel rigidlymounted at the end of the said shaft, sofas to eect-rotatio-n tendency to lose sharpness of outlineland become so much rounded at .the pointsla'sto appreciably lower the efficiency of clutch operation.'

-Y This and other objeotionshave been remedied vin the'oonstruction embodyingfthe present i'nven-Q f 7 tion by the substitution in the clutch,'for.'.the X- ternally toothed ratchet xivheel,v of anannularrng having its inner periphery cut'orformedtopro- Vide a surface comprising contiguous Vsenlicircular of the shaft and record'support. .The driving' pawl was provided with an arm extending across the axis of the shaft andin such manner asl to vlie inthe projection path 'of a"shift rod'axially disposed Within and rotatablewith said shaft.

VWhen' endivise 'movement was imparted to -the said rod by suitable clutch actuating means, thel Y end o the rod advanced so as to engage the said arm of the drive lpa'wl andfrel'easefthe pawl from engagement with the, tecth ofthe ratchetfdisc',

thus disconnecting the drive "throughthe' clutch elements.

` The clutch disclosedl ln. that application was veryeiiective in accomplishing the objects 4set forth therein, but was found, in use, to'have cer;

tain practical disadvantages. It isan objectV of thepresent invention to'provide a clutch mechanism of Vsimilar type but comprising certain l, modiiications which tend to avoid said 'disadvan tages by simplifying the structure,`l oWering the cost of manufacture, and by giving greaterfsure'f longer eiective periodjof usefulness. .j One of the principal objections t0 the formof ratchet clutch-mentioned, above resulted fromthe fact that'the driving pawl cooperated with sharp teeth disposed upon the periphery of the ratchet Wheel. n such a construction the teeth musthave mathematical precision of contour in respect to the cooperative face of the pawl, and the back and front face of each tooth must intersect in a relatively sharp point Yin order to secure satisfactory clutch operation. Thus great accuracy was required in the manufacture of the clutch parts,

particularly of the ratchet wheel, which could not readily be made by stamping or punching because of the necessary hardness ofthe metal employed if the ratchet teeth were, in use, to withstand the lgrooves s callops and, further, substituting al -pawl operating from 'Within the annulus out Y f lval'dly toward the scalloped surface, Whiclipawl is provided with a' nosesomewhat like a par-rots beak, the convex surface of which iscurvedprope 'n erly tointert'tvith .the individual scallops" formed in the. annular' ring- .V Suche" construction has the following advantageszj i (mi 'The scalloped oontourrnay readily"`belimade by punching and requires practically ,no ,c aftergrindingling j or dressing." `(b) The association of ",the. rounded. yend ofthe paWl with the-concave surfaces oi the j ring islsuch that 'the driving `'power.tends Ato set the pawl moretirlnly lin operative position (the reversefistrue'inthe case of the external ratchet andl pavvl) '(c) Y The rounded contour of 1 pawl and cooperative surface issuchthz'it Weari ofthe clutch parts tendsv toi make Vthemiitmore perf rfectly (Whereas Wear on a. ratchetv .Wheelihaving pointed 'external teeth tends 'to5ixnpair ciency and operation of the clutch). Other Vchie-cts Vwill bein part obyious andv in partpointedouthereinaitenl The'invention accordingly consists in'thegfeathe-'scope of 'the application tures ofconstructi'o'm conflloinationsY of elements,- 1 andfarrangements'of parts as willbejeiiemp'lifled inthe structure to be hereinafter described and of' which will be dicated inthe followingclaims. 'i

In'the accompanying `"drawing irl' Which is lshown one ofthe of our invention,

Various. possible embodiments Figlie a longitudinal*sfectiopalyiew of Ythe left-hand` 'portion V'of 'a Well known type' 'of diotating machine, i takenalongline 1"-1 .of Fig',4 2,

showing the driving nleanathe driven means, a clutch connection Vembodying the present'invention,l and means for operating'the clutch;

Fig.' 2 is a left end elevation of. a portionof the machine shown in Fig. 1, drawn to a largerfscale;

and

Fig. 3 is a cross-section taken on line -3 of `Fig.2. Similar reference characters referY to similarV parts throughout thevarious views of the drawheld rigidly by means of a hollow oiling stud I'IV upon a pulley bushing I8, rotatably 'mounted upon the shaft I3.v An annular ratchet A`ring I9` is rigidly mounted upon the side of the pulley I4, which faces away from thebearing- I2,and is secured to the pulley concentrically with respect to in any suitable manner, as for instance by the collar `38 whichv is slidably mounted upon the shaft I3, a pin 39 passing diametrically therethrough and through the rod 36, serving to secure these two members together for longitudinal movement relative to the shaft I3. The shaft I3 is slotted, as at', to permit this endwise movement.V This collar may be shifted in any usual manner, as by means'of a yoke 4I suitably `pivoted within the housing I I' and rockable either by hand or preferably by the electromagnetic means indicated generally at 42 in Fig. 1 of the the axis of the shaft I3 by meansof dowel pins ,I

20 and cap screws 2 I.

The inner periphery of the driving ring I3 is formed with a continuous series of semi-circular grooves or scallops, whereby the whole-inner surface of the' ring formsa curve comprising the said scallops, indicated at '22, andfthe; intervening points L23fwhere the; individual scallops adjoint one another. -Thisinner surface vof the driving ringfthus'provides a series of concave `engagement surfaces adapted to cooperate with the convex curved surface '2d of the lbealzlilre nose 25 'of a pawl 25;' This pawl is pivoted by means cfa shoulder stud 21 upon'the outer surface of a disc 23 forming part of aisleeve 29v screw-threaded into the `outer end of theshaft I3; kThis ratchet pawl isnormally held in driven contact with the inner surface ofthe ring IS'by means of a'spring 33 secured atjone end, as atBI, tothe pawl 26 and atthe other end; asat 32, tothe said disc 28. It will be seen from the foregoingthatthe ring I3 and pawl 26 constitute normally engaged elements of a clutch for transmittingpov-Jerfrom the pulley I4 to the driven shaft I3. n,

As disclosed `in Fig.',l2, 'the'pawl 26 is indented,

fered, as shown by the 'dottedjlines r34 in Figs.l 2 and, to provide camming surface adapted to belengaged by the beveled end 35'of a`clutch rod 3'6 mountedfto reciprocate' coaxially` within the bore 31 of -thezshaft I3`. ',When this rodis'provjectcd by suitable voperating mechanism outwardly beyond the disc 23,v its said beveledend 'engages the chamfered surface 34 Vof thepawl 25 with the scallop -toothed driving :ring I!! Athus rendering theclutchinoperatii/e..v Retractionof Y as at 33,' and the surface of theV indentationgcham'- Y and serves to cam Vthe pawl out ofiengagement drawing, or other suitable magnetic device. The

which reference may be had for details of construction and of operation not pertinent herein.

From the foregoing, it will be seen that the present clutch is simple of construction, may be readily manufactured, is durable, and may be used eiectively with many diiferent kinds of operating `means,'and in :use will avoid topping of the rengaging parts of theclutch in such a manner as to render clutchioperation uncertain and unsatisfactory, and that, with the present clutch, manipulation of theactuating means results in positive operating engagement of the clutch parts Without danger of slipping- We claim: 1 Y l lsf-Ina! device of thec'haracter set forth,`in combination, an exterior -member A 'rotatably mounted in coaxial-relationpwith a rotatable -interior member, a clutch element rigidly attached -to said exterior member'comprising an annular ring having its inner periphery scallopedl to providea pluralityuof'concave surfaces, a-spring Vpressedpawl pivotally'rnounted upon said'interior member having atconvex engagement surface adaptedfnorrnally to `malga driving contact'with the scalloped surface., of said annular; ring, a rod shi'ftable coaxially within said interiorinember to engage an extended portion of andtrip said pawl out of y, driving 'contact with .said annular' ring,`

:and means forV shifting said rod.

- 2. In al device ofthe character, set forth, in

combination, a driven-shaft, adrive pulley rotatable: upon said shaft Yadjacent van end thereof, an lannular ring' rigidly mounted ony said pulley in makefa'driving connection with the scalloped surfaceof said ring. a spring normally holding sadpawl in operative engagement lwith said ring,

control .means comprsinga rod Y'shiftabl'c axially"withins`aid shaft'and disc to engage an extended portion of said' pawl and' operable to trip said fpawl out of said operative` engagement. i VCHARLES L. no'ssMEtnrr-t..`A `SIMC)N YERKOVICH. A 

